That is very big mistake. There is NOTHING in the whole world that will guaranty you such uke's behavior. This is completely artificial comportment. Beginner will collapse down. Well trained attacker will enter to the legs to do take down.
You guys you reinforce some strange illusions, sorry to be honest, Dirk.

In all instances, you should work on compromising uke's balance first. The techniques come after. Szczepan is right in that a lot of beginners will collapse under a good nikkyo, and well trained attackers may go for the legs, but, when we loose our balance, our natural reaction is to try and recover it. If you don't apply the nikkyo at the right point, or the nikkyo is not on, or you deliberately haven't applied it in order to let uke think he can get up , uke may well try and stand up. One should practice for all situations, with kuzushi being the primary goal.

Bryan

A difficult problem is easily solved by asking yourself the question, "Just how would the Lone Ranger handle this?"